1. Field of Invention
The present invention relates to a multi-chip module with master-slave analog signal transmission function; particularly, it relates to a multi-chip module which transmits analog signals between chips by master-slave architecture to improve signal transmission and to alleviate wire bonding crossing problem. The present invention also relates to a signal conversion circuit and a control circuit in association with the multi-chip module.
2. Description of Related Art
A multi-chip module refers to a system which integrates multiple chips into a single module for higher packaging density, less signal delay, reduced power consumption, and lower cost. Multi-chip module technology is now widely adopted and the applications are very promising.
In a multi-chip module, signal transmission is accomplished by the wires between chips. As it is required to transmit signals among multiple chips and external circuits outside the module, the bonding wires often need to cross over one another, which adversely impacts the yield, as shown in FIG. 1.
In this regard, U.S. Pat. No. 4,627,030 discloses a dual-port memory integrated circuit. This prior art is characterized in that a master chip provides an output signal to more than one slave chip. As shown in FIG. 2, a master chip MASTER receives access requests from input pins EA and EB, and provides control signals to the slave chips SLAVE1 and SLAVE2 via the output pins ESA or ESB. The input pins EA of both slave chips are connected in common to the output pin ESA of the master chip MASTER, and the input pins EB of both slave chips are connected in common to the output pin ESB of the master chip MASTER. The drawback of the prior art is that it is only applicable to transmitting digital control signals, which must be voltage signals, but not capable of transmitting analog signals or current signals.
In view of the foregoing, the present invention provides a multi-chip module with master-slave analog signal transmission function, which not only provides a solution to analog signal transmission, but also solves the bonding wires intercrossing problem in a multi-chip module.